1. Field of the Invention
The present invention relates tires, treads, rubber compounds, additives for tires and/or treads compounds, and methods of making and using such tires and treads. In another aspect, the present invention to tread and tire additives comprising unsaturated aliphatic, cycloaliphatic and bicyloaliphatic hydrocarbons and/or olefinically unsaturated non-acidic terpene compounds, vinyl aromatic hydrocarbons and phenolic compounds, tire treads comprising such additives, tires comprising such additives, methods of making such tires, treads and tread compounds from such additives. In even another aspect, the present invention relates to tread and tire compound additives comprising unsaturated aliphatic, cyclo-aliphatic and bicylo-aliphatic hydrocarbons, and/or olefinically unsaturated non-acidic terpene compounds, vinyl aromatic hydrocarbons and phenolic compounds, tire treads and tire tread compounds comprising such additives, tires comprising such additives, methods of making such tires, treads and tread compounds from such additives, wherein such tires and treads exhibit an improved balance between wet traction, rolling resistance, abrasion resistance and steering stability.
2. Brief Description of the Related Art
A particular use, among many, of rubber compositions is for the creation of tires, such as those used in transportation, preferably automobiles. Among the many desirable attributes for tire tread compositions, a great resistance to abrasion is preferred. That is, rubber compositions that easily break down under frictional forces is not desirable because such compositions when used in a tire easily wear resulting in a short life. In addition, it is preferable that tires have very good web and/or dry grip. While dry grip is usually maintained by many rubber compositions, wet grip is not. Rubber compositions having good wet grip, thus improved wet skid resistance, is highly desirable for use in tires. Finally, it is highly desired to create a tire that helps increase the fuel economy in the transportation industry, for example in the automobile industry. One manner in which to increase fuel efficiency into a tire is to create the tire from a rubber composition that “likes” to roll. A rubber composition that “likes” to roll, in other words, has a reduced tendency to resist rolling. If a rubber composition has a reduced tendency to resist rolling, less energy is required to roll the tire. For example, less energy would be required out of the engine of an automobile if the automobile included tires made from, at least in part, rubber compositions that had a reduced tendency to resist rolling. While rubber compositions capable of being useful in tires and/or tire tread compositions are known, no such rubber composition having maximized abrasion resistance (e.g. mileage), maximized wet grip (e.g. wet skid resistance), and minimized resistance to rolling (e.g. maximizing fuel economy) is known to date.
During the 1990's, the interest of tire manufacturers in the use of resins in tire treads has increased. This interest was driven for various reasons. One is the invention of tire that is based on precipitated Silica filler technology and the use of solution styrene-butadiene rubber (SBR). The other is the introduction of Antibreaking systems (ABS) as a standard equipment of modern automobiles. In combination with ABS, the Silica fillers interacting with S-SBR with tailored micro and macro polymeric structure improve the wet traction, while they also influence the rolling resistance. Rubber formulations used in various tire components previously have been designed using conventional processing oils to soften and extend the rubber to reduce the viscosity of rubber compounds. Typically, aromatic processing oils, having a certain content of polycyclic aromatic (PCA) compounds or polyaromatic hydrocarbons (PAH), have been used. At the end of the 1990's it became apparent that the EU commission would ban such aromatic oil extenders used in tires due to their content of polycyclic aromatic hydrocarbons (PAH or PCA) by the year 2010. Distilled Aromatic Extract (DAE) is a major contributor to the dynamic properties, i.e. mainly traction due to the aromatic content. Replacement oils called non-labeled oil extenders have a lower aromatic content thus impacting negatively these desired dynamic properties. Treated Distilled Aromatic Extract (TDAE) is the alternative of choice because its impact on dynamic is less pronounced. When using Mild Extract Solvate (MES) with even less aromatic content than TDAE, there is even more so a need to compensate the drop in performance.
U.S. Pat. No. 4,701,517, issued Oct. 20, 1987 to Daughenbaugh, discloses a vinyl aromatic/terpene/phenol terpolymer having a Ring and Ball softening point of 69.degree. C. to 130.degree. C. prepared from a vinyl-substituted aromatic hydrocarbon, a monoterpene hydrocarbon and a phenol. The terpolymers are useful as tackifiers in adhesive compositions.
U.S. Pat. No. 5,723,566, issued Mar. 6, 1998, to Salvetat et al., discloses resinous copolymers comprising monomers units of each the groups of phenol compounds (I) and olefinically unsaturated non-acidic terpene compounds (II), characterized in that the copolymer contains monomer units from the group of polyunsaturated olefin compounds (III), the monomer units of compound (III) being 1% to 70% by weight of the total of the monomer units of compound (II) and (III), the monomer units of compound (II) and (III) being at least 50% by weight of the total of the monomer units of compound (I), (II) and (III). The melting point of the copolymer is at least 130° C. The copolymers can be used in inks.
U.S. Pat. No. 5,726,237 issued Mar. 10, 1998, to Satoh et al., discloses rubber compositions and pneumatic tires using the same in which the rubber compositions are used. In the rubber compositions, per 100 parts by weight of natural rubber and a conjugated diene-base synthetic rubber such as a butadiene-styrene copolymer rubber, is compounded 30 to 120 parts by weight of a carbon black having both a characteristic (concentration of >C.dbd.O functional groups)/N.sub.2 SA.gtoreq.4.0.times.10.sup.−4 and a characteristic (concentration of >C.dbd.O functional groups).gtoreq.(concentration of —OH functional groups).sup.2−0.1.times.(concentration of —OH functional groups)+0.03, or is compounded 30 to 120 parts by weight of a carbon black having the characteristic (concentration of >C.dbd.O functional groups)/N.sub.2 SA.gtoreq.4.0.times.10.sup.−4 and 0.05 to 5.0 parts by weight of at least one of a silane coupling agent, a hydrazide compound and a thiadiazole compound. The rubber compositions of the present invention and pneumatic tires using the rubber compositions excel in low rolling resistance and wet skid resistance.
U.S. Pat. No. 5,877,249, issued Mar. 2, 1999, to Lambotte, is directed to a tire with tread having silica reinforcement field. Specifically, the tread is reinforced with carbon black and precipitated silica where the tread rubbers are of a blend comprised of at least one diene-based elastomer and a styrene/α-methylstyrene resin.
U.S. Pat. No. 5,916,957, issued Jun. 29, 1999, to Itoh et al., discloses rubber compositions for tire tread that have a considerably improved rolling resistance without degrading wet-skid resistance, fracture resistance and wear resistance and comprises a particular styrene-isoprene copolymer as a rubber ingredient, in which a part or whole of the copolymer is a terminal-modified copolymer coupled at its active terminal with a particular halogenated tin compound.
U.S. Patent Application No. 20050234182, issued Oct. 20, 2005, to Kunisawa, discloses rubber compositions for tire tread, in which wet grip properties, rolling resistance, steering stability, abrasion resistance and processability are highly improved in a balanced manner. Specifically, the invention provides a rubber composition for a tread comprising (B) 30 to 120 parts by weight of carbon black and (C) 2 to 20 parts by weight of polyethylene glycol, based on (A) 100 parts by weight of a diene rubber containing 10 to 100% by weight of styrene-butadiene rubber having a hydroxyl group in the molecular chain; wherein the carbon black (B) has nitrogen-adsorbing specific surface area of 175 to 300 m.sup.2/g, cetyl trimethyl ammonium bromide oil absorption of 155 to 250 ml/100 g and iodine adsorption of 150 to 330 mg/g, and the ratio of cetyl trimethyl ammonium bromide oil absorption to iodine adsorption is 0.85 to 1.20.
U.S. Pat. No. 7,084,228, issued Aug. 1, 2006 to Labauze et al., discloses a rubber composition for a tire tread. Specifically, disclosed is a cross-linkable or cross-linked rubber composition usable to constitute a tire tread having improved wear resistance, a tread, and a tire incorporating this tread. The composition is particularly applicable to tires of passenger-vehicle type. The rubber composition includes a plasticizing resin of number-average molecular weight of from 400 to 2000 g/mol, the resin having units resulting from the polymerization of a monocyclic or bicyclic unsaturated terpene, in a mass fraction of from 70% to 100%, and having a glass transition temperature greater than 50.degree. C. and less than 120.degree. C.
Generally it is accepted by the technical community within the tire industry that tan δ measurements of a cured compound are good indicators for the expected performance of a High Performance (HP) tire. In a temperature sweep DMA the tan δ values at 0° C. are indicative for wet grip while at 60° C. they are for rolling resistance. The damping factor tan δ should be as high at 0° C., and at 60° C. as low as possible. Further, it is generally accepted by the technical community skilled in the art of compound and tire design that the dynamic storage modulus E′ at 60° C. is a good indicator for steering stability, handling and cornering of the tire while driving.
U.S. Patent Application Publication No. 20070037908, published Feb. 15, 2007, discloses rubber compositions containing improved tackifiers, and that Terpene Phenol resins with low OH value show a favorable balance between the tan δ values at 0° C. and 60° C.
All of the patents cited in this specification, are herein incorporated by reference.
However, in spite of the above advancements, there still exists a need in the art for improved tires, treads, methods of making and using, and additives for making and using.
This and other needs in the art will become apparent to those of skill in the art upon review of this specification, including its drawings and claims.